Problem: $9cd + 7ce + 10c + 6 = -2d + 10$ Solve for $c$.
Answer: Combine constant terms on the right. $9cd + 7ce + 10c + {6} = -2d + {10}$ $9cd + 7ce + 10c = -2d + {4}$ Notice that all the terms on the left-hand side of the equation have $c$ in them. $9{c}d + 7{c}e + 10{c} = -2d + 4$ Factor out the $c$ ${c} \cdot \left( 9d + 7e + 10 \right) = -2d + 4$ Isolate the $c$ $c \cdot \left( {9d + 7e + 10} \right) = -2d + 4$ $c = \dfrac{ -2d + 4 }{ {9d + 7e + 10} }$